Enhancing depth perception

ABSTRACT

Apparatuses and methods enhance depth perception, e.g., the depth perception of a human being using an apparatus worn on the user&#39;s head.

FIELD

This description relates to enhancing depth perception, e.g., enhancingdepth perception of a human being using an apparatus worn on the user'shead.

BACKGROUND

Depth perception is the ability of a human being to perceive threedimensions in the field of vision, including the distance at which aviewed object may be from the viewer. Depth perception is achieved inpart by stereopsis, which is a process by which two slightly differentimages received by two eyes can be combined to assess depth and distanceinformation by the brain. Stereopsis plays a greater role in depthperception when a viewed object is not moving or moving very slowly andalso plays a greater role in depth perception when a viewed object isrelatively close to the viewer. If a person lacks vision in one eye, theperson can still see using the remaining eye but will lack a completeability to perceive depth. Depth perception plays a key role in avariety of human activities including cutting foods, pouring liquidsinto a cup, playing sports involving catching and throwing, parking acar, sewing, firefighting, shaking hands, and aligning objects.

SUMMARY

In a general aspect, an apparatus includes: a frame configured to beworn on a human head; a rangefinder mechanism configured to measure adistance of an object, a transducer configured to receive the distancesignal from the rangefinder mechanism and configured to transmit anaudio signal; and a speaker configured to receive the audio signal andto emit an audible tone, the speaker attached to the frame. Therangefinder mechanism includes: a transmitter of a reflectable signal, areceiver of the reflectable signal, and output circuitry configured totransmit a distance signal indicative of a location of the object. Therangefinder mechanism is attached to the frame and oriented such thatthe transmitter of the reflectable signal emits the reflectable signalin a direction parallel to a line of sight of the eyes of a user wearingthe frame.

Implementations of this aspect may include the following features.

Some embodiments include a user control configured or operable to adjusta frequency range of the audio signal.

Some embodiments include a user control configured or operable enableand disable the speaker.

In some embodiments, the reflectable signal comprises an infraredsignal.

In some embodiments, the frame comprises an eyeglass frame.

In some embodiments, in which the speaker comprises a configurableoutput frequency range.

In some embodiments, the audible tone produced by the speaker changes asthe distance signal changes. In some cases, the audible tone produced bythe speaker increases in frequency as the distance signal indicates adecreasing distance. In some cases, the audible tone produced by thespeaker decreases in frequency as the distance signal indicates adecreasing distance.

Some embodiments include an eye tracker.

In a general aspect, a method includes: measuring a distance of anobject by emitting a reflectable signal in a direction parallel to aline of sight of eyes of a user wearing a frame configured to be worn ona human head; generating a distance signal indicative of a location ofthe object, the distance signal based on the reflectable signal;generating an audio signal based on the distance signal; and emitting anaudible tone corresponding to the audio signal.

Aspects can include one or more of the following advantages. A humanbeing can regain the perception of depth by audio cues provided by acomfortable and lightweight device.

Other features and advantages will become apparent from the followingdescription, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is an audio cue device.

FIG. 2 is a block diagram of electronic components.

DESCRIPTION

A device that provides audio cues about the distance of a viewed objectfrom the viewer can enhance the depth perception, for example the depthperception of a human being lacking vision in one eye. A human beinghaving vision in two eyes can perceive depth through multiple visualcues, including a method of triangulation called stereopsis. The brainperforms stereopsis by evaluating an offset of an object perceived byeach eye to determine whether the object is near to the eyes (in whichcase there is a perceivable offset) or whether the object is far awayfrom the eyes (in which case there is little or no perceivable offset).If stereopsis is not possible, for example, because one eye is impairedor lacks functionality, the device that provides audio cues about thedistance of a viewed object can substitute for traditional depthperception.

FIG. 1 shows an audio cue device 100 for enhancing depth perception. Theaudio cue device 100 provides audio cues to a human being 102 wearingthe device. The audio cue device 100 has a distance sensor 104 forevaluating distance from the human being 102 and an audio output 106 forgenerating sound representing the audio cues. The audio cues indicatedistance information to the human being 102. For example, the audio cuescan indicate information to the human being 102 about the distancebetween the human being 102 and an object in the field of vision of thehuman being 102. Here, a distant object is an object at some measurabledistance from a fixed point of view.

The distance sensor 104 is located on the audio cue device 100 near theeyes 108, 110 of the human being 102 and faces in the same direction 112as the eyes. This arrangement provides the distance sensor 104 with anunobstructed path to the same objects in the field of view of the humanbeing 102.

The distance sensor 104 can be a device that transmits a signal andreceives back the signal after it has been reflected off of a distantobject. For example, the distance sensor 104 can be a rangefindermechanism that transmits and receives back signals. One or more ofseveral different types of signals (e.g., such as infrared (optical),sonar (acoustic), radar (radio), laser (optical)) can be used. In someinstances, another signal that can be reflected back to the distancesensor 104 is used. The distance sensor 104 uses the received reflectedsignal to determine the distant object's distance from the distancesensor 104, and, therefore, approximately the distance from the humanbeing 102 wearing the audio cue device 100.

In some implementations, the distance sensor 104 measures the absolutedistance between a distant object and the distance sensor 104. Forexample, the distance sensor 104 can use triangulation, which is aprocess in which the distance sensor 104 determines the location of adistant object by measuring angles between reflected signals and fixedpoints at known locations. If the distance sensor 104 is performingtriangulation, the distance sensor 104 could transmit two signals eachhaving a point of origination offset from one another and receive thesignals reflected from the distant object. The distance sensor 104 couldthen measure the angles of the reflected signals relative to the offsetpoints of origination to calculate the absolute distance between thedistant object and the distance sensor 104.

In some implementations, the signal transmitted by the distance sensor104 provides information about the luminosity of a distant object whenreflected off of the object. Luminosity is a measure of brightness of anobject. The distance of a distant object corresponds to the measuredluminosity of the object when an optical signal is reflected off of theobject. An object that is closer to the point of transmission of theoptical signal has a greater measured luminosity than an object fartherfrom the point of transmission of the optical signal. Thus, arangefinder mechanism that uses an optical signal measures distancebased on the luminosity of a distant object when the distant object isilluminated by the optical signal. For example, a rangefinder mechanismthat uses an infrared signal measures distance based on the luminosityof a distant object when the distant object is illuminated by theinfrared signal.

The audio cue device 100 uses the distance evaluated by the distancesensor 104 to provide corresponding audio cues using the audio output106. The audio output 106 is a device such as a speaker that emits soundwaves 114 that can be detected by an ear 116 of the human being 102. Thesound waves 114 vary depending on a distant object's distance from thehuman being 102.

In some implementations, the sound waves 114 generated by the audiooutput 106 are a continuous tone that varies in frequency based on thedistance of a distant object. For example, if the distance sensor 104has determined that a distant object is relatively nearby, then theaudio output 106 generates sound waves 114 at the high end of thefrequency of audio perceivable by a human ear. If the distance sensor104 has determined that a distant object is relatively far away, thenthe audio output 106 generates sound waves 114 at the low end of thefrequency of audio perceivable by a human ear.

Upon hearing the sound waves 114, the human being 102 can evaluate thedistance of a distant object in his field of vision. A human being 102who lacks depth perception due to visual impairment and who has hadexperience correlating the perceived frequency of the sound waves 114with the corresponding distances of distant objects can regain some ofthe depth perception ability lost.

The range of potential frequencies of the sound waves 114 can be chosento correspond to the distances at which distant objects may be visibleto the human being 102 and may be similarly detectable by the distancesensor 104. The lowest frequency perceptible by the ears of the humanbeing 102 can be chosen to correspond to the farthest distance at whichan object can still be visible to the human being 102. The highestfrequency perceptible by the ears of the human being 102 can be chosento correspond to the shortest distance at which an object can still bevisible to the human being 102 (for example, immediately in front of thehuman being 102).

In some examples, a human being 102 may be able to perceive frequenciesranging from 20 Hz to 20 kHz. In these examples, the audio output 106generates sound waves 114 having a frequency closer to 20 Hz when adistant object is at the farthest distance from the human being 102while still detectable by the distance sensor 104. Also, the audiooutput 106 generates sound waves 114 having a frequency closer to 20 kHzwhen a distant object is at a very close distance from the human being102 (for example, immediately in front of the human being 102). Distantobjects of intermediate distance will cause the audio output 106 togenerate sound waves 114 having intermediate frequency relative to thedistance of the object. The frequencies can correlate to distance in alinear fashion, for example.

In some implementations, the frequencies of the sound waves 114generated by the audio output 106 can be configured to suit a particularhuman being and his range of hearing. For example, if a particular humanbeing can only perceive frequencies of up to 15 kHz, he can configurethe audio cue device 100 to a frequency range with a highest outputfrequency of about 15 kHz. Also, if a particular human being finds highfrequencies uncomfortable to hear, he can configure the audio cue device100 to a frequency range with a lower highest output frequency, such as12 kHz or 10 kHz or any other value supported by the audio output 106.

Generally, the distance sensor 104 evaluates the distance of an objectin a direct line of sight of the distance sensor 104 and thus about thesame line of sight as the human being 102 when the human being 102 islooking straight ahead relative to the position of the head. However,the distance sensor 104 could also evaluate multiple distant objectssimultaneously, for example, by sending out multiple signals reflectedoff of multiple distant objects. The audio cues provided by the audiooutput 106 could provide audio information about multiple distantobjects, for example, by providing various tones other than a continuoustone.

In some implementations, the audio cue device 100 changes theorientation or line of sight of the distance sensor 104 to correspond toa direction that an eye of the human being 102 is oriented, for example,as the human being 102 moves his pupils to track an object. For example,the audio cue device 100 could include eye tracking functionality anduse that information to control the position of the distance sensor 104.In some embodiments, audio cue device 100 includes optional eye tracker120 (e.g., a non-contact, optical mechanism for measuring eye motion).These eye trackers rely on light, typically infrared, that is reflectedfrom the eye and sensed by a video camera or some other speciallydesigned optical sensor. A control system (not shown) can be used toanalyze the reflected light to extract eye rotation from changes inreflections. The control system can adjust the orientation of thedistance sensor 104 using an adjustable mount 122.

The exemplary audio cue device 100 resembles a pair of conventionaleyeglasses and can be constructed using a conventional eyeglass frame asa base component. In some examples, the human being 102 may requirecorrective lenses to correct impaired vision in a functioning eye and sothe audio cue functionality (e.g., the distance sensor 104 and audiooutput 106) can be attached to a pair of vision-correcting eyeglasses.The eyeglass frames could also be fitted with non-corrective lenses forindividuals who do not need vision correction. In some implementations,a support structure other than an eyeglass frame can be used. Forexample, some audio cue devices include similar components mounted on ahat such as a military helmet or a construction worker's hard hat.

In some implementations, the audio cue device 100 includes user controls118. For example, the audio cue device 100 may have an on/off switchthat allows the human being 102 to deactivate the audio cue device 100when the human being 102 does not wish to hear the audio signal providedby the audio output 106. The audio cue device 100 may also have aconfigurable frequency output range and the user controls 118 couldinclude a knob or other controls that can adjust the range offrequencies produced by the audio output 106.

FIG. 2 shows a block diagram of the electronic components 200 of theaudio cue device 100. The electronic components 200 include arangefinder mechanism 202, a transducer 204, and a speaker 206. Therangefinder mechanism 202 has a signal emitter 222 and a signal receiver224. For example, the signal emitter 222 can emit a signal such as aninfrared signal, and the signal receiver 224 can receive the signal asreflected off of a distant object. The rangefinder mechanism 202communicates a distance signal 226 to the transducer 204. The transducer204 receives the distance signal 226 and converts the distance signal226 to an audio signal 242. The transducer 204 communicates the audiosignal 242 to the speaker 206 which converts the audio signal 242 toaudible sound waves 262 to be detected by a human ear. In someimplementations, the audio signal 242 is modified by another componentbefore being communicated to the speaker 206. For example, an audiocircuit 244 may increase or decrease the frequency of the audio signal242 to bring the audio signal 242 within a certain frequency range sothat the audible sound waves 262 have a desired frequency. For example,the audio circuit 244 may adjust the frequency of the audio signal 242based on settings entered using the user controls 118 (FIG. 1). In someimplementations, the audio circuit 244 is a sawtooth circuit thatoutputs a sawtooth wave.

In some examples, the electronic components 200 also include a powersource, resistors (such as resistors used to configure the signalshandled by the transducer and speaker), capacitors, inductors, and otherelectronic components. For example, the electronic components 200 can bepowered by a solar cell, a battery, another type of power source, or acombination of power sources. The audio cue device 100 could be poweredby a solar panel as a primary power source and the audio cue device 100could also include a battery as a secondary, back-up power source usedwhen the solar panel is not exposed to light.

Although the example of a human being is used, a variant of the audiocue device 100 could be used with another vision-impaired being such asan animal trained to respond to the audio cues.

Although the audio cue device 100 is described in the context ofaugmenting impaired depth perception, the device could also be used inother situations where audio cues about distance could be helpful, forexample, in a setting in which visibility is poor (e.g. a low lightsituation), a live action game, a combat setting, or an industrialsetting.

It is to be understood that the foregoing description is intended toillustrate and not to limit the scope of the invention, which is definedby the scope of the appended claims. Other embodiments are within thescope of the following claims.

What is claimed is:
 1. An apparatus comprising a frame configured to beworn on a human head; a rangefinder mechanism configured to measure adistance of an object, the rangefinder mechanism comprising: atransmitter of a reflectable signal, a receiver of the reflectablesignal, and output circuitry configured to transmit a distance signalindicative of a location of the object, wherein the rangefindermechanism attached to the frame and oriented such that the transmitterof the reflectable signal emits the reflectable signal in a directionparallel to a line of sight of the eyes of a user wearing the frame; atransducer configured to receive the distance signal from therangefinder mechanism and configured to transmit an audio signal; and aspeaker configured to receive the audio signal and to emit an audibletone, the speaker attached to the frame.
 2. The apparatus of claim 1,further comprising a user control configured to adjust a frequency rangeof the audio signal.
 3. The apparatus of claim 1, further comprising auser control configured to enable and disable the speaker.
 4. Theapparatus of claim 1, in which the reflectable signal comprises aninfrared signal.
 5. The apparatus of claim 1, in which the framecomprises an eyeglass frame.
 6. The apparatus of claim 1, in which thespeaker comprises a configurable output frequency range.
 7. Theapparatus of claim 1, in which the audible tone produced by the speakerchanges as the distance signal changes.
 8. The apparatus of claim 7, inwhich the audible tone produced by the speaker increases in frequency asthe distance signal indicates a decreasing distance.
 9. The apparatus ofclaim 7, in which the audible tone produced by the speaker decreases infrequency as the distance signal indicates a decreasing distance. 10.The apparatus of claim 1, comprising an eye tracker.
 11. A method,comprising measuring a distance of an object by emitting a reflectablesignal in a direction parallel to a line of sight of eyes of a userwearing a frame configured to be worn on a human head; generating adistance signal indicative of a location of the object, the distancesignal based on the reflectable signal; generating an audio signal basedon the distance signal; and emitting an audible tone corresponding tothe audio signal.